Conventional utility knives having disposable utility blades are well known in the art. These knives have many industrial as well as home uses, such as for opening boxes, cutting cord, or carving wall board or wood. A typical utility knife has a plastic or metal handle with either a fixed or retractable utility blade mounted therein. When in use, the blade is positioned to extend outwardly from the handle, exposing the cutting edge and one of the cutting points of the blade.
Utility knife blades come in a variety of shapes depending upon the intended use. As shown with reference to FIG. 1, a conventional utility blade has a generally trapezoidal shape that includes a back edge, a cutting edge and two side edges. The trapezoidal shaped blades are the most popular because they define sharp acute angled cutting points or tips formed at the intersections between the side edges and the cutting edge. These sharp points or tips enable a user to puncture through a material which is desired to be cut, such as sealing tape closing a box or the cardboard defining the box. Once the object has been punctured, the user can slice open the material by dragging the knife along the surface of the material and allowing the cutting edge cut through the material.
Although trapezoidal utility blades are preferred for the reasons described above, they offer the disadvantage that the tips will dull or become damaged over a period of repeated uses, rendering the blade worn out or spent. When this occurs, users that require a sharply pointed blade cutting tip will either replace the blade with a new blade, which adds to overall supply costs and material waste, or, to save money, will attempt to prolong the useful life of a spent blade by manually snapping or snipping off the end of a dulled point blade, effectively creating a new sharp cutting point. This practice is particularly cumbersome because the user has little control over where the blade will actually snap; additionally, such a practice creates a safety hazard, as the blade can shatter and project sharp metallic pieces that could harm the user or bystander. Furthermore, this practice is even more cumbersome with respect to bi-metal utility blades because the tip will not snap off manually thereby requiring the use of a cutting tool to renew the tip.
To address this disadvantage, conventional snap-off style utility blades have been developed that employ an elongated blade having a plurality of blade segments separated by score lines that allow the user to snap off a spent blade segment at the respective score line. However, such snap-off style utility blades require a specialized blade holder and utility knife housing to secure, move and index the blade, and cannot be used with conventional retractable and fixed blade utility knives that use conventional trapezoidal utility blades.
There is a need, therefore, for an improved utility knife blade that overcomes one or more of the above-described drawbacks and/or disadvantages of conventional prior art utility knife blades and conventional prior art snap-off style utility knife blades.